Gun sight and mounting



33-252. OR 2;.3459363 SR March 28, 1944.

F. M. SMITH GUN SIGHT AND MOUNTING Filed Sept. 29, 1942 Search Rem Kay.4.

( 8% y (L rorflq'y' Patented Mar. 28, 1944 I Search teem GUN SIGHT ANDMOUNTING Frank M. Smith, Lynn, Mass.

Application September 29, 1942, Serial No. 460,056 In Canada July 2,1942 Claims.

My present invention relates to guns and more particularly to gunsights. It is a well recognized fact in modern warfare that it is verydifficult for a gunner to make hits on fast moving targets in the airwhich are continuously changnot only necessary to make allowances forspeed 3' with respect to time but also to accurately figure the angle ofapproach of the plane and furthermore, the gunner must make allowancesfor speed and time. In other words, the gunner must determine the angleof approach of the plane and actually shoot a predetermined distance infront of the plate if he is to score a hit.

The most difiicult operation is to accurately gauge the angle ofapproach because unless the gunner is shooting at a point interceptingthis line of travel of the plane he is either overshooting,undershooting, or otherwise missing the plane altogether. On the otherhand, if the gunner is shooting on a line which will intercept the planehe is quite likely to hit it even though some of his shots are a bit toofar in advance.

In all such instances, it is to be assumed that the gunner is using arapid fire gun such as large caliber machine guns and the like which arecapable of discharging a large number of bullets or shells per minute.Of course in the case of timed shells which are set to explode at apredetermined distance from the gun, a large rate of discharge perminute is not so important but the distance from the target is importantand introduces another factor not specifically concerned with myinvention. However, I wish to make it clear that my invention may alsobe applied to larger caliber guns than those falling within the rangeof, so called, machine guns.

In my present invention, I have designed a gun sight for machine gunsand the like which enables the gunner to determine the angle of approachof the plane so that he can operate his machine gun on the angle ofapproach whether or not it be in a vertical plane or at any angle to thevertical by the simple manipulation of the sight mounted on the gunbarrel.

The principal object of my invention is an improved gun sight.

Another object is an improved gun sight which may be mounted on the gunbarrel of a machine gun which is fixed against rotation with respect tothe major axis of the barrel or, it may be mounted on an infantry armsuch as a rifle either of the single shot, semi-automatic, or fullautomatic type.

Still another object is an improved gun sight which may be rotated aboutthe center of the major axis of the gun barrel, either to the right orleft, as the case may be, so that the angle of approach of the plane maybe graphically determined and at the same time estimate the speed of theplane so that the gunner will have a close estimate of the point tostart shooting at in order to intercept the plane when it arrives atthat position, and

Other objects and novel features comprising the construction andoperation of my invention will be apparent as the description of thesame progresses.

In the drawing illustrating the preferred embodiment of my invention:

Fig. 1 is a side elevation of a machine gun, the gun proper beingsomewhat in diagrammatic form but showing the gun sight and operatingmechanism mounted on the gun barrel;

Fig. 2 is a partial cross-section and rear elevation of the gun sight,as viewed from the gunners position, the scale being greatly enlarged,and the position of the cross-section being indicated by the numerals2--2, as indicated in Fig. 1;

Fig. 3 is a partial cross-section and elevation taken on the line 3-3 ofFig. 2, and

Fig. 4 is an extreme rear elevation of the rear sight and the controlknob of the front sight,

. the lower portions of the gun being broken away.

Referring more in detail to the drawing, l0 indicates a machine gunmounted on any suitable gun mounting such that the gun barrel I2 may bepivoted up or down or swung from right to left, as conditions mightrequire.

On the breech end of the gun I0 is fixed a rear sight member l3 which isprovided with a peep hole l4 through which the gunner looks when he isbringing the front sight into alignment with the particular spot atwhich he intends to shoot.

0n the front end of the gun barrel I2 is mounted my improved gun sight,a portion of which is rotatably controlled by means of the hand wheel l5and shaft I 6.

The forward gun sight comprises a stationary ring portion II, thelowermost portion of which is provided with a split collar portion I 8through which is inserted the end of the gun barrel II, the collarportion l8 being securely clamped to the barrel I2 by means of the screwbolt I9. To prevent the ring portion H from rotating on the barrel I2 Ihave milled a round groove on the under side of the barrel which isengaged by the body of the bolt I9 thereby preventing any rotatablemotion between the ring IT and the barrel I2.

In Figs. 2 and 3, I have shown the forward gun barrel sight in detail,and by an inspection of Fig. 3 it will be noted that within the ring I!I have located a second ring 26. This ring 20 is held in place, as shownin Fig. 3, within the apparatus by an outer flange member 2I which issecured to the permanent ring II by any suitable means, as the rivets22. The ring 20 is rotatable and for the purpose of controlling therotation thereof, I have provided an annular rack 23 comprising a partof the ring 20 with which is engaged a pinion 24 which is fixed to theshaft I6. It will thus be apparent that when the shaft I6 is rotated bythe gunner, the ring 20 may be rotated in the ring IT.

The ring I1 is further provided with a series of horizontally spacedwires 25. The graduations of the spacing of these wires 25 may be fixedas desired.

Within the rotatable ring 20 I have also provided a series of spacedwires 26. In both sets of wires 25 and 26, it will be observed that Ihave provided a small wire ring 25a and 26a both of which are inalignment with the peep hole I4 of the rear sight I 3, and an axial linedrawn through these openings is parallel with the longitudinal axis ofthe gun barrel I2.

It will be apparent that when the gunner rotates the shaft I6 the ring20 will rotate within the rin I! causing the wires 26 to assume variousangles, as shown in dot-and-dash lines, in Fig. 2, the openings in thelittle wire rings 25a and 26a always being in alignment with the peepopening I4 in the rear sight I3.

The purpose of the wires 26 in the rotatable ring 20 is for aligning theangle of approach of an airplane approaching the vicinity of the gunnerso that he can automatically obtain the correct angle of approach of theplane and can shoot at a spot in advance which will intercept the plane.

The wires 25 are used as a gauge in estimating the amount of lead toallow for the speed of the airplane as it travels along one of the wires26. If the airplane is estimated to be a certain number of yards awayand traveling a certain speed it will cross one of the spaces betweentwo of the wires 26 in a certain number of seconds thereby giving thegunner a rough estimate of how many spaces to allow in order to be sureto intercept the said airplane.

It will be apparent that the gunner may vary the angle of the wires 26at will as he follows the line of travel of the plane and when the planeis within range of his gun he starts shooting at a spot in advance ofthe plane but on an angle which will intercept the plane and evenalthough his estimate of distance is inaccurate if he holds the targeton the proper angle and continues to fire he is very sure ofintercepting the airplane.

It will thus be apparent that although I have disclosed my invention inconnection with machine guns its application to guns of higher caliber,such as anti-aircraft guns is just as applicable, and whereas I haveshown the apparatus somewhat in detail as to parts, it is to be assumedthat I may vary the shape and proportions, or I may substituteequivalent means of operation to properly carry the invention intooperation well within the spirit of the appended claims.

Having thus described my invention what I claim as new is:

1. An improved gun'sight for guns, rifles and the like comprising incombination, a front sight comprising an aperture having a plurality offixed vertical lines, the said aperture being fixed to the said gun, asecond aperture having a plu rality of rotatable parallel lines locatedconcentric with the first aperture, and means controlled from the breechend of the gun for rotating said second aperture and parallel lines topresent varying angles with the vertical lines on the fixed aperture.

2. An improved gun sight for gun barrels and the like comprising incombination, a front sight unit comprising an annular ring fixed to thefront end of said gun barrel and having a plurality of fixed verticaland parallel lines extending across the internal diameter of said fixedring, a second ring mounted adjacent said first ring having a pluralityof fixed horizontal lines extending across the said second ring, andmeans for rotating said second ring relatively to said first ring, saidsecond ring being operated from the breech end of said gun.

.3. In a gun sight for machine guns, rifles and anti-aircraft guns, aring having a plurality of vertical lines permanently fixed ontheforward end of a. barrel of said gun, a rotatable ring mountedadjacent the first said ring and having a plurality of parallel linesrotatably movable with respect to the parallel lines in said first ring,means connected with the breech end of said gun for rotating the secondring and lines against the fixed lines in said first ring.

4. In a gun sight for machine guns, rifles and other guns, a fixed ringmounted on the forward end of the said gun having a plurality of fixedspaced vertical lines and a central sight aperture, a second ringmounted adjacent to the said first ring also having a central sightaperture and parallel lines, means for rotating said second ring againstfirst lines in said first ring, said means operated from the breech endof said gun for rotating said second ring.

5. In a gun sight for gun barrels and the like, the combination with agun barrel, comprising a forward open ring fixed to said barrel having acentral aperture with parallel spaced wires, a rotatable open ringmounted adjacent and concentric with said first ring and having a secondconcentric central aperture and parallel spaced wires,- said second ringbeing rotatable relatively to said first ring and having an attachmentlocated adjacent the breech end of the gun for rotating

